add serverless lwa doc

config/_default/menus/main.en.yaml

@@ -3162,6 +3162,11 @@ menu:
       parent: serverless_aws_lambda
       identifier: libraries_integrations
       weight: 111
+    - name: Lambda Web Adapter
+      url: serverless/aws_lambda/lwa
+      parent: serverless_aws_lambda
+      identifier: serverless_aws_lambda_lwa
+      weight: 112
     - name: AWS Step Functions
       url: serverless/step_functions
       parent: serverless

content/en/serverless/aws_lambda/lwa.md

@@ -0,0 +1,225 @@
+---
+title: Lambda Web Adapter
+further_reading:
+    - link: '/serverless/configuration/'
+      tag: 'Documentation'
+      text: 'Configure Serverless Monitoring'
+    - link: "/integrations/amazon_lambda/"
+      tag: "Documentation"
+      text: "AWS Lambda Integration"
+---
+
+{{< callout url="#" btn_hidden="true" header="Join the Preview!" >}}
+Lambda Web Adapter is in Preview.
+{{< /callout >}}
+
+## Overview
+
+The AWS [Lambda Web Adapter][1] is a framework that allows developers to run web applications on AWS Lambda. 
+
+Datadog supports Lambda Web Adapter for Node.js and Python runtimes, therefore providing you a solution to monitoring your web applications running on AWS Lambda.
+
+## How to integrate Datadog
+
+The Lambda Web Adapter can run Lambda functions that are packaged as docker images or as Zip files. The following steps are required for instrumenting the Lambda Web Adapter with Datadog for both formats:
+
+1. [Add the Lambda Web Adapter and Datadog extension](#1-add-the-lambda-web-adapter-and-datadog-extension)
+2. [Set the required Datadog environment variables](#2-set-the-required-datadog-environment-variables)
+3. [Ignore tracing for the readiness endpoint](#3-ignore-tracing-for-the-readiness-endpoint-required-only-when-using-datadog-tracing) (_*required only when using Datadog tracing_)
+
+#### 1. Add the Lambda Web Adapter and Datadog extension
+
+{{< tabs >}}
+{{% tab "Container deployment" %}}
+This configuration requires Datadog Lambda extension `v77+` and Lambda Web Adapter `v0.9.1+`. See a sample of the container deployment configuration on [Github][2].<br><br>
+
+```Dockerfile
+COPY --from=public.ecr.aws/datadog/lambda-extension:77 /opt/. /opt/
+COPY --from=public.ecr.aws/awsguru/aws-lambda-adapter:0.9.1 /lambda-adapter /opt/extensions/lambda-adapter
+```
+
+[1]: https://github.com/awslabs/aws-lambda-web-adapter
+[2]: https://github.com/awslabs/aws-lambda-web-adapter/tree/main/examples/datadog
+[3]: https://github.com/awslabs/aws-lambda-web-adapter/tree/main/examples/datadog
+{{% /tab %}}
+
+{{% tab "Zip deployment" %}}
+This requires Datadog Lambda extension `v77+` and `v25+` or later for Lambda Web Adapter. See a sample of the Zip deployment configuration on [Github][3]. 
+
+
+**for x86**
+
+```shell
+arn:aws:lambda:${AWS::Region}:464622532012:layer:Datadog-Extension:77
+arn:aws:lambda:${AWS::Region}:753240598075:layer:LambdaAdapterLayerX86:25
+```
+
+**for ARM**
+```shell
+arn:aws:lambda:${AWS::Region}:464622532012:layer:Datadog-Extension-ARM:77
+arn:aws:lambda:${AWS::Region}:753240598075:layer:LambdaAdapterLayerArm64:25
+```
+[1]: https://github.com/awslabs/aws-lambda-web-adapter
+[2]: https://github.com/awslabs/aws-lambda-web-adapter/tree/main/examples/datadog
+[3]: https://github.com/awslabs/aws-lambda-web-adapter/tree/main/examples/datadog
+{{% /tab %}}
+{{< /tabs >}}
+
+#### 2. Set the required Datadog environment variables
+{{< tabs >}}
+{{% tab "Container deployment" %}}
+
+Since there is no explicit shutdown system for Lambda, traces must be flushed as soon as possible so they are not lost when the Lambda runtime environment is "frozen". 
+
+The transparent tracing requires the Datadog extension to also proxy requests before the Lambda Web Adapter, so the `AWS_LWA_LAMBDA_RUNTIME_API_PROXY` must be set to allow that. The port can be set with any available port.
+
+```bash
+DD_TRACE_PARTIAL_FLUSH_MIN_SPANS=1
+DD_TRACE_PARTIAL_FLUSH_ENABLED=false
+
+AWS_LWA_LAMBDA_RUNTIME_API_PROXY=127.0.0.1:9002
+
+DD_API_KEY=$YOUR_API_KEY
+DD_SERVICE=$YOUR_SERVICE_NAME
+```
+
+[1]: https://github.com/awslabs/aws-lambda-web-adapter
+[2]: https://github.com/awslabs/aws-lambda-web-adapter/tree/main/examples/datadog
+[3]: https://github.com/awslabs/aws-lambda-web-adapter/tree/main/examples/datadog
+{{% /tab %}}
+
+{{% tab "Zip deployment" %}}
+
+Since there is no explicit shutdown system for Lambda, traces must be flushed as soon as possible so they are not lost when the Lambda runtime environment is "frozen". 
+
+The transparent tracing requires the Datadog extension to also proxy requests before the Lambda Web Adapter, so the `AWS_LWA_LAMBDA_RUNTIME_API_PROXY` must be set to allow that. The port can be set with any available port.
+
+```bash
+DD_TRACE_PARTIAL_FLUSH_MIN_SPANS=1
+DD_TRACE_PARTIAL_FLUSH_ENABLED=false
+
+AWS_LWA_LAMBDA_RUNTIME_API_PROXY=127.0.0.1:9002
+
+AWS_LAMBDA_EXEC_WRAPPER=/opt/bootstrap
+
+DD_API_KEY=$YOUR_API_KEY
+DD_SERVICE=$YOUR_SERVICE_NAME
+```
+[1]: https://github.com/awslabs/aws-lambda-web-adapter
+[2]: https://github.com/awslabs/aws-lambda-web-adapter/tree/main/examples/datadog
+[3]: https://github.com/awslabs/aws-lambda-web-adapter/tree/main/examples/datadog
+ {{% /tab %}}
+{{< /tabs >}}
+
+#### 3. Ignore tracing for the readiness endpoint
+\*_This step is required only when using Datadog tracing_.
+{{< tabs >}}
+{{% tab "Container deployment" %}}
+
+Since the Lambda Web Adapter sends readiness check requests once it is loaded, the Datadog extension must not link them to the request that triggered the Lambda function. 
+
+The configuration differs depending on the runtime. Assuming the readiness endpoint is the default (`GET` at `/`):
+
+**NodeJs**
+
+```js
+const tracer = require('dd-trace').init();
+tracer.use('http', {
+    blocklist: ['/']
+});
+ ```
+
+**Python**
+
+```python 
+import ddtrace
+
+ddtrace.patch_all()
+from ddtrace.trace import tracer, TraceFilter
+...
+class IgnoreEndpointFilter(TraceFilter):
+    def __init__(self, pattern, method):
+        self.pattern = re.compile(pattern)
+        self.method = method
+
+    def process_trace(self, trace):
+        for span in trace:
+            url = span.get_tag("http.url")
+            if (
+                url is not None
+                and self.pattern.match(url)
+                and self.method == span.get_tag("http.method")
+            ):
+                return None
+        return trace
+
+
+tracer.configure(
+    trace_processors=[IgnoreEndpointFilter(r"http://127.0.0.1:8080/", "GET")]
+)
+```
+[1]: https://github.com/awslabs/aws-lambda-web-adapter
+[2]: https://github.com/awslabs/aws-lambda-web-adapter/tree/main/examples/datadog
+[3]: https://github.com/awslabs/aws-lambda-web-adapter/tree/main/examples/datadog
+ {{% /tab %}}
+
+{{% tab "Zip deployment" %}}
+
+Since the Lambda Web Adapter sends readiness check requests once it is loaded, the Datadog extension must not link them to the request that triggered the Lambda function. 
+
+The configuration differs depending on the runtime. Assuming the readiness endpoint is the default (`GET` at `/`):
+
+**NodeJs**
+
+```js
+const tracer = require('dd-trace').init();
+tracer.use('http', {
+    blocklist: ['/']
+});
+```
+
+**Python**
+
+```python
+import ddtrace
+
+ddtrace.patch_all()
+from ddtrace.trace import tracer, TraceFilter
+...
+class IgnoreEndpointFilter(TraceFilter):
+    def __init__(self, pattern, method):
+        self.pattern = re.compile(pattern)
+        self.method = method
+
+    def process_trace(self, trace):
+        for span in trace:
+            url = span.get_tag("http.url")
+            if (
+                url is not None
+                and self.pattern.match(url)
+                and self.method == span.get_tag("http.method")
+            ):
+                return None
+        return trace
+
+
+tracer.configure(
+    trace_processors=[IgnoreEndpointFilter(r"http://127.0.0.1:8080/", "GET")]
+)
+
+```
+[1]: https://github.com/awslabs/aws-lambda-web-adapter
+[2]: https://github.com/awslabs/aws-lambda-web-adapter/tree/main/examples/datadog
+[3]: https://github.com/awslabs/aws-lambda-web-adapter/tree/main/examples/datadog
+ {{% /tab %}}
+{{< /tabs >}}
+
+
+
+## Further Reading
+
+{{< partial name="whats-next/whats-next.html" >}}
+
+[1]: https://github.com/awslabs/aws-lambda-web-adapter
+[2]: https://github.com/awslabs/aws-lambda-web-adapter/tree/main/examples/datadog
+[3]: https://github.com/awslabs/aws-lambda-web-adapter/tree/main/examples/datadog